Guide elements



United States Patent Office Patented Sept. 6, l66

3,270,937 GUIDE ELEMENTS William Albright Harrell, Grifton, N.C.,assignor to E. I. du Pont de Nemours and Company, Wilmington, Del., acorporation of Delaware Filed Nov. 27, 1964, Ser. No. 414,158 2 Claims.(Cl. 226-197) This invention relates generally to textile apparatus andto a method for converging strands of continuous filaments into a tow orrope suitable for crimping and, more particularly, to textile apparatusfor stacking individual ribbons of fibers to form a tow.

Synthetic fibers are spun in units of several thousand filaments andseveral of these units or bundles (ribbons) are then combined to form atow or rope of several hundred thousand denier which is then crimped.The crimped tow can then be spun into yarn by one of the conventionaldirect spinning methods by means of the Turbo Stapler or the PacificConverter or it may be cut into staple fiber which is then carded andspun on either the cotton or woolen spinning systems. In either case itis necessary for the fiber to be crimped; and, if uniform yarns are tobe spun, the tow must be uniformly crimped.

The stacking of individual ribbons into a tow is one of the mostcritical operations in the production of uniformly crimped tows. Thickareas in the tow will result in fiber damage because of the excessivesqueeze roll pressure in the crimper and slippage of the crimper rolls.Thin areas in the tow will result in uncrimped or poorly crimpedfilaments. Poor crimping also results from variations in the tow width.Split tows will cause uneven crimping and also make subsequentoperations more difficult.

Accordingly, an object of this invention is to provide means and amethod for the uniform stacking of the individual bundles or ribbons offibers into a tow. Other objects will appear hereinafter.

The objects of this invention are accomplished by providing in anapparatus for continuously receiving a plurality of separate movingribbons of filaments which comprises means vertically aligning eachmoving ribbon in a spaced relationship and means converging to form atow having the moving ribbons uniformly stacked and a width equal tothat of a single ribbon, the improvement wherein the converging meanscomprises a base plate having a plurality of cantilevered guide elementsmounted thereon, the guide elements each having a portion having anovalshaped guide surface with a radius of curvature in the range of fromabout inch to about 3 inches, the guide elements being positioned on thebase plate in such a manner that each guide element guides a singleribbon to a common convergence point, the ribbons contacting the guideelements on the oval-shaped surface.

The embodiments of this invention and their advantages can be morereadily understood by referring to the accompanying drawings:

FIGURE 1 is a side elevation view showing an apparatus utilizing oneembodiment of this invention and illustrating five ribbons beingconverged by means of five guide elements,

FIGURE 2 is a side elevation view of the embodiment of the inventionshown in FIGURE 1,

FIGURE 3 is a front elevation view of one of the guide elementsillustrated in FIGURE 2,

FIGURE 4 is a side elevation view of the guide elements shown in FIGURE3, and

FIGURE 5 is a sectional view taken generally along line 5-5 of FIGURE 2.

The general arrangement utilizing the preferred embodiment of thisinvention is best shown in FIGURE 1.

A supporting frame structure 20 extends vertically upward from asupporting base member 22 and 24. Adjustably mounted between theextremities of the supporting frame structure 20 are a plurality ofvertically extending supporting beams 26. The supporting beams 26 may bemade of suitable angle brackets the ends of which are slidably securedby suitable means such as threaded nuts 28 and bolts 30 in slots in theupper and lower horizontal elements of frame structure 20. These anglebrackets 26 may be adjusted in the horizontal direction, and preferablyeach functions to individually support one of a plurality of firstrotatable means or first stage guide units 32.

A plurality of second means which comprise a second stage guiding andarranging assembly 34 are mounted in operative association with thesupporting frame structure 20, the first stage guide units 32, and theplurality of moving spaced, relatively narrow filament bundles orribbons generally designated by the numeral 36. The second stageassembly 34 may either be mounted in an extended portion (not shown) ofthe frame 20, or it may be aifixed to other suitable structure.

Each of the first stage guide units 32 generally comprises a supportingbracket, a beam member, a roll supporting and canting means, and arotatable roll as shown in US. Patent No. 3,145,429. The supportingbracket is adapted for vertical positioning movement within the frame 20by means of its slidable locking engagement in an extended slot providedin the vertically extending angle bracket 26. Angle brackets 26 may berotatably mounted at each end by suitable conventional means, not shown,for rotary movement about a vertical axis, swinging beam member in ahorizontal plane. This arrangement permits alignment of the axis of therotatable roll perpendicular to ribbon 36. The beam member is mounted insupporting bracket 28 by suitable bolts or screws.

As best shown in FIGURE 2, the second stage guiding and arrangingassembly 34 represents the preferred embodiment of this invention andcomprises a base plate 2 mounted upon rod 4 (supported by means notshown) and adjusting set screws 6 securing rod 4 in position as.desired. Corresponding in number to the number of ribbons 36, which areforwarded from a drawing operation not shown, guide elements 8 arerotatably mounted on base plate 2 and secured by set screws 10.

FIGURES 3 and 4 show in detail guide elements 8. Each guide elementconsists of a shaft portion 12, which is mounted in base plate 2, and anoval-shaped portion 14 integral therewith.

FIGURE 5 illustrates the plurality of ribbons 36 after they have beenstacked in an aligned vertical relationship.

The operation should be readily apparent. As disclosed in US. Patent No.3,145,429, the roller convergence guides are so arranged that eachconcave roller can be tilted to guide the various ribbons from lateraladjacent positions as they come from a textile processing step such as adrawing operation to an alignment in a vertical plane as each ribbonapproaches its respective guide element. The oval-shaped surface of theguide element provides a relatively large area in contact with theribbons which change direction only slightly. The greater area ofcontact (as compared to a circular guide) provides the desired amount offriction on the ribbon to maintain sufficient tension as the ribbons arefirmly stacked in a vertical aligned relationship. After contacting theguide elements, the ribbons converge to stack in a vertically alignedrelationship.

Table I below illustrates the improvement in tow quality resulting fromuse of the guide elements of this invention in comparison with a singlepound bar. The tow was composed of a 3 denier per filament (.33 Tex.)polyethylene terephthalate fiber. The tow quality index (TQI) is ameasure of tow defects per unit of tow produced. Both major and minordefects were counted. Each period represents a three-month operatingperiod during which more than several hundred thousand pounds of fiberswere processed.

The face of the oval-shaped extremity must have a radius of curvature inthe range of from about /s inch to about 3 inches, preferably about inchor more. Table II, below, illustrates measurements of the guide elementswhich will be suitable for most purposes.

Table II Measurement, Part: inches Shaft portion- Length 2% Radius /2Oval-shaped extremity Length 2%; Long radius Short radius Width Depth AIf round bars were to be used in place of the guide elements of thisinvention, diameters twice the radius of curvature of the oval-shapedextremity would have to be used to give the same area of contact.Moreover, the guide elements allow a wide variation in contact areasince they can be rotated to any desired position.

The guide elements can be made of any hard, corrosion-resistantmaterial. For example, stainless steel number 304 with a chromium-platedsurface and finished to a matte surface of 75 to 95 micro inches R.M.S.has been found to be satisfactory.

Although the description hereinbefore has illustrated only five guideelements, it should be obvious that the number may be more or less,depending, of course, upon the number of ribbons which are to be used toform the tow. Also, the shape of the base plate, as shown in spect tothe positioning of the guide elements relative to each other, anyarrangement can be used as long as the ribbons are converged to a commonpoint.

The guide elements can be advantageously utilized to form a large deniertow from several ribbons formed of any synthetic fibers, such aspolyamides, polyacrylics, polyolefins and polyamides.

The novel guide elements of this invention have been illustrated inconjunction with the roller convergence guides disclosed in US. Patent N0. 3,145,429. However, the invention should not be so restricted; and itshould be obvious that the novel guide elements can be used with anysuitable means which can provide a plurality of ribbons in a spaced,aligned vertical plane as the ribbons approach the guide elements.

This invention has provided novel means to accomplish the stacking of aplurality of ribbons in a vertical aligned relationship to form a tow ofuniform width and thickness. This has resulted in a reduction in towdefects, as shown in Table I, of about 56 percent and is an importantstep in producing good quality fibers and fabrics.

Since many different embodiments of the invention may be made withoutdeparting from the spirit and scope thereof, it is to be understood thatthe invention is not to be limited except to the extent defined in thefollowing claims.

What is claimed is:

1. In an apparatus for continuously receiving a plurality of separatemoving ribbons of filaments which comprises means vertically aligningeach moving ribbon in a spaced relationship and means converging saidribbons to form a tow having said ribbons uniformly stacked and a widthequal to that of a single ribbon, the improvement wherein saidconverging means comprises a base platev having a plurality ofcantilevered guide elements mounted thereon, said guide elements eachhaving a portion having an oval-shaped guide surface with a radius ofcurvature in the range of from about /s inch to about 3 inches, saidguide elements being positioned on said base plate in such a manner thateach guide element guides a single ribbon to a common convergence point,said ribbons contacting said guide elements on the oval-shaped surface.

2. The apparatus of claim 1 wherein said radius of curvature is greaterthan inch.

References Cited by the Examiner UNITED STATES PATENTS 3,145,429 8/1964Resor 281 M. HENSON WOOD, JR., Primary Examiner.

I. N. ERLICH, Assistant Examiner.

1. IN AN APPARATUS FOR CONTINUOUSLY RECEIVING A PLURALITY OF SEPARATEMOVING RIBBONS OF FILAMENTS WHICH COMPRISES MEANS VERTICALLY ALIGNINGEACH MOVING RIBBON IN A SPACED RELATIONSHIP AND MEANS CONVERGING SAIDRIBBONS TO FORM A TOW HAVING SAID RIBBONS UNIFORMLY STACKED AND A WIDTHEQUAL TO THAT OF A SINGLE RIBBON, THE IMPROVEMENT WHEREIN SAIDCONVERGING MEANS COMPRISES A BASE PLATE HAVING A PLURALITY OFCANTILEVERED GUIDE ELEMENTS MOUNTED THEREON, SAID GUIDE ELEMENTS EACHHAVING A PORTION HAVING AN OVAL-SHAPED GUIDE SURFACE WITH A RADIUS OFCURVATURE IN THE RANGE OF FROM ABOUT 5/8 INCH TO ABOUT 3 INCHES, SAIDGUIDE ELEMENTS BEING POSITIONED ON SAID BASE PLATE IN SUCH A MANNER THATEACH GUIDE ELEMENT GUIDES A SINGLE RIBBON TO A COMMON CONVERGENCE POINT,SAID RIBBONS CONTACTING SAID GUIDE ELEMENTS ON THE OVAL-SHAPED SURFACE.